In the present study, we investigated plant communities with Yellow Oat Grass (Trisetum flavescens (L.) Pb.) in the submontane and montane regions of Slovenia. In 2005-2007 ninety-one relevés were collected by using the standard procedure of the Braun-Blanquet approach. Relevés were analysed with multivariate analysis and classified within two associations: Astrantio-Trisetetum (Polygono-Trisetion) and the Pastinaco-Arrhenatheretum (Arrhenatherion). Management practices, soil conditions and altitude were found to be significant factors for a further subdivision of both associations. Within the Astrantio-Trisetetum association three subassociations could be distinguished: -typicum, -buphthalmetosum and -trollietosum, and subassociations -typicum, -medicagetosumlupulinae, as well as -lolietosum subass. nova in the Pastinaco-Arrhenatheretum. The floristic composition and ecological characteristics of these plant communities are described and their implications for grassland conservation in Slovenia are discussed. V članku predstavljamo rezultate raziskave vegetacije travišč s prevladujočim rumenkastim ovsencem (Trisetumflavescens) v submontanskih in montanskih predelih Slovenije. V letih 2005-2007 smo popisali 91 vegetacijskih sestojev po standardni Braun-Blanquetovi metodi. Na osnovi multivariatnih analiz smo uvrstili travišča v dve asociaciji, in sicer v asociacijo Astrantio-Trisetetum (zveza Polygono-Trisetion) in asociacijo Pastinaco-Arrhenatheretum (zveza Arrhenatherion). Nadaljnja členitev na nižje sintaksonomske enote obeh asociacij je pogojena predvsem s stopnjo intenzivnosti upravljanja s travišči, z različnimi edafskimi razmerami in nadmorsko višino. Tako ločimo v asociaciji Astrantio-Trisetetum naslednje sintaksone: subasociacije -typicum, -buphthalmetosum in -trollietosum, v asociaciji Pastinaco-Arrhenatheretum pa: -typicum, -medicagetosum lupulinae in -lolietosum subass. nova. Predstavljene so floristična sestava asociacij, njune ekološke značilnosti in varstveni vidiki obravnavanih travišč.